COLLOQUIUM: Prof. Martin Pohl, DESY Zeuthen
When: Wed, 08.05.2024 2:00 PM until 3:30 PM
Where: Hamburger Sternwarte, Gojenbergsweg 112, 21029 Hamburg, Bibliothek
Misaligned jets: from formation to dissipation
Decades of astrophysical research have left the process of jet formation and acceleration in Active Galactic Nuclei (AGN) as a central unsolved problem. Using high-resolution VLBI at mm wavelengths, we find evidence for magnetic acceleration by the black hole and accretion disk in the innermost jet expansion region. On the other hand, the international LOFAR telescope has made big progress at longer wavelengths, providing high-resolution images of AGN host galaxies. So far, high-resolution VLBI studies have been focused on bright, one-sided and strongly Doppler boosted AGN jets as in M 87, which is the basis for our understanding on AGN. However, for an all-inclusive physical description we have to include all flavors of AGN jets at all possible jet powers and all scales. Combining AGN studies across the radio spectrum, from LOFAR wavelengths to mm-VLBI, is crucial to unraveling the underlying physics of jet formation, acceleration, collimation, and their interplay with host galaxy properties.
To work towards this goal my research is focused on nearby AGN with misaligned jets, a subset of which shows doubled-sided jets allowing to study the symmetry in these systems. I will show examples on how VLBI helps us to uncover the processes of jet expansion and evolution with a focus on radio galaxies, specifically NGC3894 and NGC1052, and discuss our chances of extending these pursuits through future advances, represented by the ngVLA and the SKA.
Talk in presence and via Zoom:
https://uni-hamburg.zoom.us/j/66006535328?pwd=aGkrSjJIYmZjK0VpYlpGL0ZrdHg2UT09
Meeting ID: 660 0653 5328
Passcode: 20658852